Consensus Lacking on COPD Classification, Say Researchers

Competing standards for evaluating chronic obstructive pulmonary disease (COPD) could lead to errors in both diagnosis and treatment, according to a Medscape Medical News article reporting from CHEST 2011: American College of Chest Physicians Annual Meeting.

Important differences exist in the way patients are classified by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the American Thoracic Society/European Respiratory Society (ATS/ERS), said Ameer Rasheed, MD, in presenting the results of a study on the issue.

To see how different the standards are, Rasheed and his colleagues retrospectively reviewed the records of 217 patients with a COPD diagnosis and applied the 2 different standards to them.

They found that there was a discordance in diagnosis in 24 (11%) of the patients. Twenty patients, with a median age of 64 years, met the GOLD criteria for COPD but not the ATS/ERS criteria, whereas 4, with a median age of 41 years, met the ATS/ERS criteria but not the GOLD criteria. Based on the results, researchers concluded that older patients might be overdiagnosed and younger patients underdiagnosed, says the article.

An additional 39 patients were categorized as mild by ATS/ERS but moderate by GOLD.

Under GOLD, a patient should be diagnosed with COPD if the patient's forced vital capacity divided by forced expiratory volume in 1 second (FEV1/FVC%) is below 70. Under ATS/ERS, COPD is diagnosed when FEV1/FVC% is less than the lower limit of normal established by the National Health and Nutrition Examination Survey.

A patient is classified as "mild" if the FEV1/FVC is over 80% under GOLD, but 70% under ATS/ERS. A patient is "severe" if that measurement is 50%-80% under GOLD, but 50%-70% under ATS/ERS.

"Severe" is 30%-49% under GOLD but 35% -49% under ATS. "Very severe" is less than 30% under GOLD and less than 35% under ATS/ERS.

Brian W. Carlin, who co-moderated the session, said that the discrepancies are particularly important for mild to moderate patients. GOLD is expected to introduce revised standards in a few months, but he acknowledged that it might be too early to forge a consensus on guidelines, the article says.